In a series of unusually strict directives, Chinese officials have announced new bonuses for couples with no more than one and income cuts, housing and promotion restrictions for families that grow beyond two children.

The toughened birth sanctions apparently grew from a major Peking conference on population control in January. They reflect widespread official distress at the state of the economy and the difficulties of modernizing a country with 900 million mouths to feed.

A difficult reappraisal of China's economic nees, continuing in a series of high-level meetings, has even produced a startling official admission by Radio Peking that "the average amount of food grain distributed to each person in China is now even less that in 1957."

Even if each married woman only had two children, said a broadcast from Guangdong Province, the ancestral of most Chinese Americans, the province's population would still increase by 10 percent in the next five years and "any improvement in the people's living standards can be forgotten."

Nationally, the numbers are even more staggering. The country's annual population growth has been estimated at 1.5 to 2 percent. Although that is below such countries as India, with more than 2 percent, or Mexico, with more than 3 percent, the growth represents an increase of 13 to 18 million Chinese a year. The higher estimate would mean China grows every year by about the population of the state of New York.

Birth control is nothing new in China. It is even mentioned in a new constitution approved last year. Shanghai was reported two years ago to have reduced its population growth rate to only 0.6 percent through a tough system that required every woman to report her contraception method to local authorities and then wait until she was told it was her turn before having a baby.

But China's national leaders have never been as blunt about their population problems as they seem to be now, or as willing to impose sanctions on parents seeking a third or fourth child. As in other countries with population control has been particularly strong among peasant couples who depend on sons to help run farms, earn food for the family and support elderly parents.

Strong birth-control measures, sometimes including forced sterilization, encountered similar tradition-based opposition in India and contributed to the popular dissatisfaction that drove former prime minister Indira Gandhi from office.

Official Chinese broadcasts have complaines of even local Communist Party leaders being "influenced by old customs and traditional ideas." Five members of a county party committee in Guangdong were singled out for producting at least five children each, and one had seven. Perhaps in anticipation of the difficulties of birth control in Guangdong, big, freshly printed official posters announcing in details the new sanctions on too many children have gone up in the provincial capital, Canton.

The nurse at the Xiangyang Farming Brigade of 2,000 persons outside Wuhan said she has recorded only six births - and at least six abortions - in the last year, reflecting the spirit of the new sanctions.

The regulations, reported in varying degrees of detail by Guangdong, Sichuan, Shanxi and Anhui provinces, appear to follow a central directive. An Anhui broadcast this month said:

A worker or official who produces a third or additional child will have 5 percent deducted from the family income for welfare expenses. A peasant who has a child will have 5 percent of his annual workpoints, which are labor shares use to determine his percentage of the harvest, deducted each year and added to the local welfare fund. The deduction will increase to 6 percent for a fourth child and 7 percent for a fifth child.

Officials or workers who had health expenses paid by the state in the past, and have a third or additional child, must pay medical bills from the pregnancy out of their own pockets, except in emergency cases. The child may not be covered by local medical insurance plans.

Before the age of 14, a third or additional child will not receive ration coupons for any commodities other that rice and cotton. If the family gets into financial trouble, no subsidies will be paid.

Couples who have a third or additional child will get no extra housing space if they live in the city, or no extra private plot area for vegetable growing if they live in the country.

Couples who have just one child, however, will get extra money for health expenses and an adult grains rations for the child. Urban couples with one child will be put to the top of the waiting lists for new housing and receive the same floorspace as families with two children, the Anhui broadcast said.

In Sichuan, an only child will qualify for preferential treatment in school admissions and job assignments. Good colleges and urban jobs bring steady incomes and welfare advantages that parents can ill afford to pass up for their children. Such incentives become very attractive, despite the Chinese reluctance to risk old age on the support of just one child.

The official New China New Agency said, "People. . . in every walk of life warmly support the publication of the new measures." But it will be sometime before China knows how effective its new sanctions are in pulling down the growth rate.

Chairman Hua Guofeng has called for a decline to 1 percent. Some large cities and provinces claim they already have attained this goal. But foreign analysts, suspicious of Chinese population figures, cannot verify the claims. Chinese leaders themselves also have occasionally expressed doubts.